Influence of acclimatization time on barometric whole-body plethysmography in cats with lower airway disease.

Abstract

BACKGROUND: Barometric whole-body plethysmography (BWBP) is used as a noninvasive method to assess lung function in cats with lower airway disease (LAD). The duration of the acclimatization period in the measuring chamber varies between the studies. OBJECTIVES: To assess the influence of acclimatization time on variables indicative of lung function. ANIMALS: Twenty-four client-owned cats with LAD and 8 healthy cats. METHODS: In the prospective case-control study for each cat, a 30-minute dataset was collected. Data for the three 10-minute periods were statistically compared. RESULTS: The variables pause (T1 median: 0.8, range: [0.7-1]; T3: 0.9 [0.8-1.1]; P ≤ .01), peak inspiratory flow (PIF; T1: 84.9 [71.6-112.7]; T3: 75 [63.6-108.3]; P ≤ .001), peak expiratory flow (PEF; T1: 53.2 [41.5-76.6]; T3: 42.5 [34.6-57.8]; P ≤ .01), and a quotient of PEF and expiratory flow at 50% expired volume (PEF/EF50; T1: 1.2 [1.1-1.4]; T3: 1.2 [1.1-1.5]; P ≤ .01) varied significantly between first and third time period in cats with LAD. In healthy cats PIF (T1: 76.4 [66.3-85.2]; T2: 69.5 [58.3-85.2]; P ≤ .01), PEF (T1: 40 [32.8-58.6]; T2: 34.3, [29.8-44.6]; P ≤ .01), and PEF/EF50 (T1: 13.1 [11.6-14.6]; T3: 13.6 [12.4-16.3]; P ≤ .01) changed significantly between first and second time period. Enhanced pause did not change significantly in either group. CONCLUSIONS AND CLINICAL IMPORTANCE: Acclimatization time has a significant influence on multiple variables in BWBP. Manual correction of the data for tidal breathing flow-volume loop might be necessary.